[Octave-bug-tracker] [bug #51871] loading '-ascii' format files is slow

[Dan Sebald]

Follow-up Comment #8, bug #51871 (project octave):

Good point, testing for 'N' before 'n' and 'A' before 'a' will likely save a
few cycles for canonical files.  I was just thinking back on Intel x86
instructions, and it wouldn't surprise me if an instruction could be packed
with 8 bits for op-code and 8 bits operand so that something like str_chunk[0]
== 'N' could be very fast, and keeping operands in registers rather than
swaping them out and back in is always good.  (A good optimizing compiler
would figure that out.)

Of course, it all depends on how often this particular bit of code gets
called, and there are likely other locations consuming enough cycles that such
optimizing is irrelevant, so benchmark.  There have been similar Octave
functions where successive tweaking has made a noticeable difference.

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